/*******************************************************************************************
 * Copyright (c) 2006-2009 Alex Robson, Rob Simmons, Craig Israel, and Rachel Twyford
 *
 * Use of this software in any form requires that you have both 
 * read and agreed to the following terms:
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions: 
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, 
 * this list of conditions and the following disclaimer in the 
 * documentation and/or other materials provided with the distribution.
 * Neither the name of Nvigorate nor the names of its contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ****************************************************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using Nvigorate.Common;
using Nvigorate.Data;
using Nvigorate.Data.Query;
using Nvigorate.Relational.Builders;
using Nvigorate.Relational.Mapping.Index;
using Nvigorate.Relational.Mapping.Interface;
using Nvigorate.Relational.Repository;

namespace Nvigorate.Relational.Visitors
{
    public abstract class TypeVisitorBase
    {
        protected List<ITargetRelationship> _visited = new List<ITargetRelationship>();

        public virtual bool Visited(ITargetRelationship relationship)
        {
            if (relationship == null)
                return false;
            return _visited.Contains(relationship) || _visited.Any(r => r.IsInverse(relationship));
        }
    }

    public class SelectVisitor : TypeVisitorBase, ITypeVisitor
    {
        protected IDatabaseProvider _provider;
        protected ILoadInstruction _instruction;
        protected IRepositoryMapIndex _repositoryMapIndex;

        private readonly List<Insert> _insertIntoHoldingTables = new List<Insert>();
        private readonly List<Select> _selectFromHoldingTables = new List<Select>();
        private readonly List<TableVariable> _holdingTables = new List<TableVariable>();

        public List<ITargetRelationship> Visited { get { return _visited;  } }

        public SelectVisitor(ILoadInstruction instruction, IDatabaseProvider provider, IRepositoryMapIndex maps)
        {
            _instruction = instruction;
            _provider = provider;
            _repositoryMapIndex = maps;
        }

        public void Visit(Type type)
        {
            Visit(type, null, "");
        }

        public void Visit(ITargetRelationship relative, string suffix)
        {
            _visited.Add(relative);
            Visit(relative.RelativeType, relative, suffix);
        }

        protected void Visit(Type type, ITargetRelationship owner, string suffix)
        {
            var builder = new SelectBuilder(_repositoryMapIndex, type, owner, suffix, _instruction);
            _holdingTables.Add(builder.HoldingTable);

            _insertIntoHoldingTables.Add(builder.InsertIntoHoldingTable);
            _selectFromHoldingTables.Add(builder.SelectFromHoldingTable);
        }
        
        public QueryList GetQuery()
        {
            var query = new QueryList();
            query.AddRange(_holdingTables.Cast<IQueryObject>());
            query.AddRange(_insertIntoHoldingTables.Cast<IQueryObject>());
            query.AddRange(_selectFromHoldingTables.Cast<IQueryObject>());
            return query;
        }

        public List<string> TableNames
        {
            get { return _holdingTables.Select(t => t.Table.Name).ToList(); }
        }
    }
}